Chelsea’s defense of the Premier League title has been dealt a serious blow as Antonio Conte prepares to be without two of his key players for up to six weeks, reports say.

The Italian’s team has slipped to six points behind joint leaders Manchester City and Manchester United, both on 19 points after seven games. But there was still hope for Chelsea, given the team’s run of wins after a poor start last season.

Now Conte looks likely to be without Alvaro Morata and N’Golo Kante until at least the middle of November. Kante was key to the Chelsea team that won the title last season, and the Leicester City side that won it the season before. He has been shortlisted for the Ballon d’Or, football's highest honor for individual players.

Morata only arrived in England in July, becoming Chelsea’s most expensive signing ever, but his importance to Conte’s project has become apparent immediately: The 24-year-old Spaniard has already scored eight goals in 10 appearances. But a hamstring strain, suffered in the defeat to Manchester City, was said to keep him sidelined for between four and eight weeks.

While on international duty with France, Kante has been hit with a similar injury. The industrious midfielder was forced off in France’s World Cup qualifying victory over Bulgaria on Saturday. Early suggestions, according to the Daily Telegraph, are that Kante could be out for at least three weeks, which would see him miss crucial Champions League games.

Roma travel to London on Wednesday for the Group C tie, before Chelsea make the journey to Italy a fortnight later. The list of league games both players could miss includes trips to Crystal Palace and Bournemouth, as well as Watford at Stamford Bridge and Everton in the League Cup.

Jose Mourinho will be back in west London on November 5 when his United team comes to Stamford Bridge, a game Conte will be keen to have Kante and Morata back for, as his team will need to be at full strength.